1. Field of the Invention
The present invention relates to a transmission apparatus having a plurality of network interfaces and a transmission method using a plurality of the network interfaces, and more particularly, to a transmission apparatus such as a terminal having a plurality of network interfaces capable of efficiently utilizing network resources by distributing network traffic over a plurality of the network interfaces and a transmission method using a plurality of the network interfaces.
2. Description of the Related Art
Recently, communication terminals such as mobile phones, PDAs, and notebook computers having various network interfaces for connection to a plurality of networks and for reception of various services instead of a single communication network have been provided. For example, a mobile phone which supports CDMA and WLAN and a PDA which supports CDMA and WiBro are provided. In a notebook computer, a WLAN network interface is basically provided, and a card for connection to other networks such as a PCMCIA interface card may be additionally provided.
In the fourth-generation network technology, various networks are provided simultaneously. For example, various wireless networks such as CDMA, WLAN, WCDMA, HSDPA, and WiBro networks are provided simultaneously, and a user can connect to desired networks through a suitable communication terminal having wireless cards.
Such wireless networks have a slower communication rate than that of a cable high speed communication network, and a data transmission rate may be lowered according to a wireless connection environment.
In such an environment, a user having a communication terminal capable of connecting a plurality of wireless networks can distribute traffic over a plurality of the wireless network through simultaneous connection to a plurality of the wireless networks simultaneously. In this case, in comparison with connection to a single network, the user can utilize wide bandwidth, and stable communication performance can be maintained even in an unstable wireless connection environment.
In addition, traffic can be distributed according to characteristics of services. Therefore, high quality services can be maintained. For example, in a terminal which supports HSDPA and WLAN, a user can receive a high-quality moving picture streaming service through the HSDPA and a file downloading service through the WLAN simultaneously. In this case, the bandwidth for the moving picture streaming service through the HSDPA can be maintained in the existing bandwidth. However, in a terminal which can connect only one wireless network, a limited bandwidth is divided for the two types of services. Therefore, the quality of the moving picture streaming service may be lowered, or the download rate of the file downloading service be lowered.
As a result, preferably, a terminal connects a plurality of the networks simultaneously, and traffic is distributed according to types of services. In addition, a method of efficiently distributing the traffic is required. In addition, in order to provide such services, a multiple-mode terminal which can connect a plurality of the networks simultaneously through hardware or software network interfaces is required.